A school system could be paying five times too much for care at the lowest-quality facility in its ZIP code. More effective care is likely available for less money at a different hospital, lab, or imaging center just around the corner.

The Obama administration gave conditional approval Monday to Arkansas, Delaware and Pennsylvania to expand their roles in the insurance marketplaces created under the 2010 health care law, ahead of a high court decision that could wipe out federal health insurance subsidies for millions.